From f26c7d414357baaa38c2971c1884bb63c3d664c8 Mon Sep 17 00:00:00 2001
From: Bailey Ling <bling@live.ca>
Date: Fri, 4 Oct 2013 10:27:49 -0400
Subject: [PATCH] echo warning message if duplicate statusline func gets added.

---
 autoload/airline.vim | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/autoload/airline.vim b/autoload/airline.vim
index 133da4f..c4c7d77 100644
--- a/autoload/airline.vim
+++ b/autoload/airline.vim
@@ -11,6 +11,12 @@ function! airline#add_statusline_func(name)
 endfunction
 
 function! airline#add_statusline_funcref(function)
+  if index(g:airline_statusline_funcrefs, a:function) >= 0
+    echohl WarningMsg
+    echo 'The airline statusline funcref '.string(a:function).' has already been added.'
+    echohl NONE
+    return
+  endif
   call add(g:airline_statusline_funcrefs, a:function)
 endfunction